In a copending application Ser. No. 759,489 filed Sep. 13, 1991 and assigned to a common assignee, there is disclosed a system, described as a fuzzy syllogistic system that utilizes a circuit called an inference block in which separate first and second input terminals are provided respectively with a first analog signal whose amplitude is linearly related to the truth measure of the minor premise of the syllogism and with a second analog signal whose amplitude is linearly related to the truth measure of the major premise to yield an output whose amplitude is that of the second analog signal so long as the amplitude of the second analog signal is at least as great as the value of the complement of the first analog signal and preferably greater than the value of the complement by a prescribed amount that can be chosen to compensate for noise in the system. If this inequality is not satisfied, it is concluded that the truth value of the minor premise is insufficient to reach an inference from the major premise. This application is incorporated herein by reference.
Moreover, for use when the fuzzy information system involves a multistage link chain of inferences, as is often the case in real life situations, there is included a separate inference block for each inference of the chain paired with a special circuit that provides as an output the smaller of two input analog signals. The separate inference blocks each with its paired special circuit are connected in a chain with the output of a preceding inference block supplying one input to the subsequent inference block and the other input being supplied with the truth measure of the major premises of the successive inferences. This system will be discussed more fully in connection with FIG. 1 of the drawing.
Such a system can be relatively complex when used with a chain of several or more sequential inferences. A possible application of a system of this kind is as a control for a process that includes a sequence of interrelated operations or measurements whose accuracy or confidence values are less than unity and some measure of the confidence in the final measurements or guestimates of the process is desirable.